Science

In essence, sound is actually a wave generated by the vibration of the object, the sound waves in the air is actually a "longitudinal wave"

There is a view that the reason why the Earth looks round is because of the role of the Earth's oceans, which simply means that a large amount of seawater has "filled in" the undulations of the Earth's surface.

The "four great beasts" of physics actually exist only in thought experiments, and their proposal helps to develop and improve the relevant theories

The reason we don't see time travelers is actually because they are not in our timeline

It has long been discovered in practice that the phenomenon of "gravitational time dilation" does exist

Although ultra-pure water does not exist in nature, humans can prepare it themselves

Earthquakes are a common natural phenomenon. On average, millions of earthquakes occur on Earth every year, except that most of them are so mild that they are largely imperceptible to humans.

The law of conservation of momentum means that the total momentum of a system remains constant when it is not subject to external forces or when the sum of the vectors of external forces is zero

The energy released by nuclear fusion is actually an important basis for stars to be able to maintain their stability

The Arecibo Radio Telescope in the United States used to be the largest radio telescope in the world, with a diameter of 350 meters. As the most powerful radio telescope ever built, scientists have achieved many scientific results with the radio Arecibo radio telescope in the past decades